title: Removal of natural organic matter by cationic hydrogel with magnetic properties.
abstract: Magnetic cationic hydrogel (MCH) was synthesized, and its removal efficiency and mechanisms in regard to natural organic matter (NOM, represented by humic acid and fulvic acid) from the aqueous environment were studied. The effects of time, adsorbent dosage, initial pH, ionic strength, background ions, and NOM types were also investigated. MCH was characterized and found to have a strong magnetic character, yielding an extra advantage for recycling and reuse. Batch studies showed that the removal of Aldrich humic acid (AHA) by MCH was effective. The main mechanism for the removal of NOM is believed to be due to electrostatic interaction. NOM with larger molecular weight tended to be preferentially removed. Solutions with low pH, high ionic strength, and background electrolytes containing calcium, sulfate and bicarbonate were unfavorable for AHA removal. The adsorption-desorption of MCH was evaluated in three cycles, and demonstrated high regeneration rates.
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Pinhua
authors.initials: P
authors.lastname: Rao
authors.forename: Irene M C
authors.initials: IM
authors.lastname: Lo
authors.forename: Ke
authors.initials: K
authors.lastname: Yin
authors.forename: Samuel C N
authors.initials: SC
authors.lastname: Tang
mesh_terms: D000327:Adsorption; D001578:Benzopyrans; D002851:Chromatography, High Pressure Liquid; D006812:Humic Substances; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008280:Magnetics; D013997:Time Factors; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods
chemical_list: D001578:Benzopyrans; D006812:Humic Substances; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C005023:fulvic acid